Sensor networks are used in many application areas, such as biomedical sensors, predictive maintenance and RFID tags, which generally needs a long lifetime and small sizes [1]. For these systems emerges the necessity to develop energy harvesting integrated circuits. With no batteries we can develop sensors that has a longer lifetime, are smaller and, possibly, cheaper.

This project consists in a temperature sensor tag powered by an RF signal emitted by a reader. The readerreceives the reflected signal from the tag, which contains information on the temperature measured. The Figure 1 shows a block diagram of the system containing the blocks to be implemented.

Figure 1: Block diagram of the system

The blocks are listed below:

Impedance Matching: matches the input impedance of the rectifier to the antenna impedance. It assures the maximum power is transmitted to the rectifier [2];

Rectifier (RF-DC): converts a high frequency AC signal to DC [3];

Voltage Limiter: limits the output voltage of the rectifier, so that it remains in a safe level [4][5];

Voltage Regulator: regulates the voltage that will be used to power the sensor. This voltage isn’t dependent of temperature [5];